A known lens drive unit for an imaging device mounted in a cellular phone incorporates a smooth impact drive mechanism (SIDM: a registered trademark).
Japanese Unexamined Patent Publication No. 2015-089183, for example, discloses a lens drive unit that incorporates the smooth impact drive mechanism. This lens drive unit comprises an actuator having one end fixed to a base member, a drive shaft joined with the other end of the actuator, and a friction engagement unit frictionally engaging an outer periphery of the drive shaft. In the lens drive unit described above, extension and contraction of the actuator is imparted to the drive shaft and the friction engagement unit frictionally engaging the drive shaft with a predetermined friction force is driven by making use of a difference in speed between when the actuator extends and when the actuator contracts.
The friction engagement unit includes a lens frame fitted with a lens having an optical axis extending in parallel with a direction of extension and contraction of the actuator. Causing the friction engagement unit to advance and retract in the direction of extension and contraction of the actuator results in the lens frame advancing and retracting.
In the lens drive unit described above, the lens frame of the friction engagement unit is displaced with respect to the base member in a direction orthogonal to the direction in which the friction engagement unit advances and retracts to press the drive shaft by impact from an outside of the lens drive unit or the like. In this case, the piezoelectric actuator is inclined with respect to the base member.
The present disclosure provides a lens drive unit that prevents an inclination of the actuator.